Howto add a 12V to 5V DC/DC Converter with USB Phone Plug

To go with my Fork/Stem Tube RAM Phone Mount I've added a simple 12V to 5V DC/DC Converter with an integrated right angle USB-C connector (you can also get them with USB micro-B connectors if you have an older phone). I mounted it to one side of the black bracket that holds the headlight housing. I pulled switched 12V power from the horn and ran a fresh ground line back to the battery. I added a Dust Cap for the USB-C connector to protect it when not inserted into the phone.

It's a bit hard to see the Converter (it tucks in there nicely!) and I took the pictures before ZipTie-ing the cables out of of the way to make it easier to see what's going on. I tried to "highlight" my additions and the black wire that I ran to make it easier to see. You can also add a magnet (with superglue and fusion tape) to the USB-C connector to stick it to the frame when not in use.

Mounting the Converter

The converter barely fits on the inside of the headlight housing bracket, and in fact your screws holes will not quite be on the same surface (the bracket has a slight bend do it near the fork) but that is ok because the Converter mounting tabs are plastic and can flex a slight bit.

1. Place painters tape on the both sides of the bracket you intend to drill to protect the finish
2. Place the DC/DC converter on the inside of the bracket where it will live, ensure it doesn't interfere with the headlight housing. I actually used two converters (one on the outside and one on the inside) and lined them up together and then used the outside one to mark the location (then I discarded that spare converter). Make sure you aren't too far "back" (toward the seat) so that it is challenging to drill the rear hole.
3. I didn't ever remove the headlight housing but it would probably have been a lot easier if I had. If you want to, this is the time to do it. Make an indention with a Center Punch (to ensure you drill bit doesn't wander)
4. Drill a small pilot hole
5. Drill a larger hole to accept a #8 or M4 screw (I used a size 14 bit). You may want to add several layers of tape to the fork when drilling the rear hole to protect it from the side of the bit.
6. Remove the tape and install the Converter using stainless steel #8 or M4 screws (approx 5/8" or 16mm long), washers, and nylock nuts.

Wiring

1. Crimp male 1/4" quick disconnects to both the red & black wires on the Converter.
2. Disconnect the orange wire from the Horn & cut the female 1/4" quick disconnect off as close to the connector as possible. Strip back 1/4" of insulation to expose the copper wire.
3. Get a yellow 1/4" quick disconnect (for heavier 10-12 gauge wire) and insert the original horn power wire as well as a length of spare orange wire (approx 1 foot). Crimp it. Reinstall the quick disconnect to the horn.
4. Ensure there is enough length on your spare orange wire to reach the red input wire to the Converter (approx 6"), cut it to length, strip back 1/4" and install a red (preferably insulated) female 1/4" quick disconnect.
5. Plug the red wire from the converter into the new orange section from the horn power.
6. Remove the grommet around the big wire harness that comes out of the frame opposite the electrical on/off lock.
7. Use a fish tape from the battery/gas tank compartment toward the front and pop it out the opening where you removed the grommet (this was actually much easier than I expected).
8. Tape on a black ground wire and pull it back through. Leave plenty of slack on both ends.
9. Reinstall the grommet
10. Route the wire around the gas tank and battery to the negative terminal on the battery.
11. Crimp/solder a battery terminal lug to the wire and attach it to the battery (I put this in the same lug as I used for my SAE Battery Tender Connector)
12. Go back to the front (near the grommet) and route the black wire to the black input on the Converter.
13. Cut your black wire to length, install a 1/4" female quick disconnect.
14. Connect the new ground wire to the black wire from the Converter
15. Route the USB output of the Converter up to where your phone mount is and zip tie it in place.
16. Clean up the rest of the wiring wiring and zip-tie it out of the way

Shopping List

1. 12V to 5V DC USB Type-C Right Angle Power Converter 15W
2. Lugs for Battery Terminal
3. Dust Cap to protect USB-C connector
4. stainless steel #8 or M4 screws (approx 5/8" long), flat washers, nylock nuts
5. 1/4" Quick Disconnect Kit
6. Fish Tape
7. Crimp Tool
8. (optional) soldering iron & solder (depending on type of battery lugs)
9. Zip Ties

Alternate USB Micro-B Parts for Older Phones

1. Dust Cap to protect USB Micro-B connector
2. 12V to 5V DC USB Micro-B Power Converter 15W

Photos